A machining operation for the removal of material from a workpiece is typically performed by rotating a workpiece and operating upon the workpiece with a cutting insert held by a toolholder which is not rotating. The toolholder may be positioned relative to the workpiece such that a variety of applications including parting, grooving, face grooving or profiling may be performed upon the workpiece. However, typically, a toolholder and insert are designed to perform one and possibly two of these applications and, for that reason, a complete set of tooling hardware often involves a number of different toolholders and cutting inserts, each dedicated to a limited range of applications.
In each of these applications, it is desirable to maintain the insert securely within the toolholder and also to positively locate the insert within the toolholder thereby providing machining operations with a high level of accuracy.
U.S. Pat. No. 4,801,224 by Pettersson et al, entitled "Tool and Insert for Chip Removal", teaches a cutting insert which is clamped by a toolholder having a resilient clamping arm. The clamping arm contacts a planar abutment surface on the insert body to position the insert against the clamping arm within the toolholder. However, the contact area between the clamping arm and the insert body is fairly small and provides limited stability to the insert.
Additionally, the cutting insert rests on a longitudinal surface which is parallel to the feed direction of the tool. As a result, a vertical force on the cutting insert will not urge the insert into the pocket of the toolholder.
An object of this invention is to provide a cutting insert and a toolholder for the same such that forces during the cutting operation act upon the insert to stabilize the insert within the holder.
Another object of this invention is to provide an insert and toolholder design which permit positive mechanical retention of the insert within the toolholder.
Another object of the invention is to provide a positive stop within the toolholder such that the insert may be mounted within the toolholder and positioned at a known location within the toolholder.
Another object of the invention is to provide a cutting insert and toolholder design that will allow for a large number of machining applications using a variety of different inserts which are compatible with the toolholder. In this manner the number of toolholders may be reduced.
Still another object of this invention is to provide a cutting insert and toolholder in which the toolholder contacts the insert in at least three distinct locations.
Another object of the invention is to provide a standard cutting insert body which is compatible with a toolholder but with a cutting area on the body which may be customized to fit the machining operation application.